The residential and commercial roofing industry in the United States is a billion dollar industry annually. The majority of this demand is in non-residential construction, particularly office/commercial space and institutional construction. There are a variety of roofing techniques and procedures that can be used for such structures, depending upon environmental conditions, building construction, costs, and availability of materials.
One of the most common types of non-residential roofing construction is built-up roofing (BUR), also known as low-slope roofing. Historically, BUR systems have been popular because of their proven stability and reliability. BUR structures over 30-40 years old in excellent condition are not uncommon. BUR is also easy to install and maintain, relatively inexpensive, and widely available. For this reason, it is expected to be widely popular for many years to come.
BUR usually comprises multiple layers of coal tar pitch or asphalt, referred to as “bitumen”, spread between multiple plies of roofing sheets or felts. Bitumen is a solid or semi-solid material that is usually melted and applied to saturate and seal multiple plies or felts across a roof surface. The melting of bitumen is often done on-site utilizing any of a variety of specially designed kettles or pots. The melted bitumen is often pumped from a kettle to a roof top through a series of joined pipe segments, usually referred to as “thinwall tubing”, rising to a roof top where it is expelled and spread across the roof.
The optimal melting temperatures of bitumens vary with each type of material. For example, asphalt, a solid material, has a melting point between approximately 54° C. to 173° C. and an auto-ignition point of >400° C. The optimal working temperature of asphalt is approximately 300°. In contrast, coal tar pitch, a thick paste material, will become more liquid at temperatures between approximately 30° C. to 180° C. and has an auto-ignition point of >500° C. The optimal working temperature of coal tar pitch is similar to that of asphalt.
Thus, when the temperature of these materials falls below the melting or liquid point they can begin to solidify or thicken, which can block or clog the transfer pipes. Once the pipes become blocked, they must be disassembled and cleaned or “melted-out” before they can be used again to transfer material. The longer the melted bitumen stays within the transfer pipes, the greater the chance of transfer pipes becoming blocked as the bitumen cools. It is not uncommon for transfer pipes to become blocked numerous times during a roofing installation.
The current techniques for melting-out blocked pipes or thinwall tubing are often time-consuming and energy inefficient and can slow down roofing installation and raise overall costs. For example, the most common technique uses an industrial blow-torch to heat the length of the tubing in order to re-melt the solidified or thickened material within. The efficiency of this method depends upon a variety of factors, including the number of people and blow-torches available to melt-out the tubing, the skill of the person(s) using the blow torch, the severity of the blockage, the number of blocked thinwall tubes, and the length of the pipe(s), etc.
The subject invention provides devices and methods for more efficiently melting-out clogged or blocked thinwall tubing. The devices and methods of the subject invention can be used at almost any location, including on-site of a roofing project, and, in certain embodiments, are capable of simultaneously melting-out a plurality of tubes or similar equipment.